Slasher48,
I checked the site and you hit it on the head: 25 is what they claim. I then went back to Magnecore's site and read why ultra-low resistance is not necessarily better (go figure!) In any case, I don't think the pinging is caused by your wires, but it's no doubt a sign of pre-ignition. Did you check TDC on your #1 cylinder? If you changed the timing belt or reset the cams recently, you could have jumped timing a bit. The other possibility that springs to mind is the knock-sensor(s)'s connection to the ECU could have broken or shorted. I don't know how many there are on the 2JZ.
I still like the Bosch +4 for NAs, 4418 for 7M and 4417 for 2JZ.
I run 93 with timing at +13: never pings even pulling away at 4MPH in second gear. (Just trying to save those 15 year old synchronizers on first!)